The traditional method for informing consumers of item prices in a retail setting is to place price labels on the shelves under the items. These labels are normally made of paper or of another single-use material and must be manually updated when prices change or when an item goes on sale. There are many advantages to making this item information available electronically including greater accuracy, lower labor costs, greater flexibility, and more timely and responsive pricing practices. To achieve these advantages, electronic shelf labels may be placed on the shelves. Retailer merchandisers place electronic shelf labels on stock shelves to display item information such as the regular product price, any promotional pricing, and the unit price of the item, as well as any other advertising or consumer information. Electronic shelf labels may also be remotely updated from a central pricing database. Electronic shelf labels enable merchants to update price changes on the shelves and checkout stands of multiple stores at the same time.
These electronic shelf labels are programmed using radio frequency or infrared (IR) interfaces, or by wiring the shelves to accept periodic inputs from another device. But there are disadvantages to pricing methods using electronic shelf labels. Power and communication means must be provided to the individual labels. If batteries are used to provide power to each label, they must be changed on a regular basis. With 30,000 items in a supermarket, this could be prohibitive. Wired shelves do not require the routine change of batteries, but they limit a store's ability to reallocate shelf space and reconfigure the shopping aisles by moving display shelves since each shelf is now specifically wired for a particular product.
Additionally, electronic shelf labels do not provide the consumer with item information in a side-by-side comparison of similar products. The consumer must manually locate and inspect each individual electronic shelf label and use these individual labels to mentally track and compare quantities, pricing, and other unique item data. Similar products may be located further down the aisle or on a shelf higher or lower than the consumer is able to properly perceive or comfortably investigate. Comparisons are often made only between two adjacent items, and the consumer is not able to adequately evaluate his retail alternatives. In fact, suppliers pay thousands of dollars in slotting allowances to distributors for product placement on store shelves. Premiums are paid for eye-level shelves or special displays, and an entire science of shelf space allocation has evolved so suppliers may increase the likelihood that consumers will consider their products and ultimately select those products for purchase. However, neither electronic shelf labels nor paper labels adequately provide consumers with readily comparable item data from which to base their purchase decisions.
What is needed is a new type of item information system that provides consumers with unique item data and enables consumers to make immediate comparisons between similar items resulting in an informed purchase decision.
In another approach, price-checking stations have been provided in retail environments that are adapted to read a barcode and provide price information. More recently, radio frequency transponders have been proposed to replace barcodes in a wide variety of applications. Such radio frequency transponders are typically capable of receiving a radio frequency interrogation signal and automatically generating a responsive radio frequency signal. In many applications, the responsive signal contains some form of data that identifies the transponder or that identifies items associated with the transponder. Radio frequency transponders are often embedded in products or product containers and are used to track items for inventory control, for performing security operations and anti-theft measures, for collecting tolls and other payments, and for many other purposes.
Radio frequency transponders can be active devices that have internal power source and have their own radio frequency transmitters that can generate signals using the internal power source, or passive devices, that do not have an internal power source and that can provide responsive signals only when sufficient power is supplied by an interrogation signal. Radio frequency transponders may have a range from several millimeters to many meters depending upon the available transmission power and antenna size. Radio frequency transponders employing on-board power supplies have a life limited by the life of the power supply. Passive radio frequency transponders have a longer useful life and are typically less expensive than radio frequency transponders with on-board power supplies. However, since radio frequency transponders without their own power source use some of the energy of the radio frequency transceiver as their source of their power, these radio frequency transponders typically require a more powerful radio frequency interrogating signal than a system that employs active radio frequency transponders.
A radio frequency transceiver transmits an interrogation signal, for example, in the form of continuous electromagnetic wave or a series of waves to sense an object containing a radio frequency transponder. When the radio frequency transceiver and a radio frequency transponder are brought into proximity so that the radio frequency field generated by the radio frequency transceiver reaches the radio frequency transponder, the receiving radio frequency transponder transmits a modulated signal in response to the radio frequency transceiver's interrogation signal. The radio frequency transceiver receives this information and decodes it. Depending upon the configuration of the radio frequency transceiver, this decoded information may then be stored or re-transmitted to a host computer for further processing and action.
While the potential convenience of placing such radio frequency transponders on individual products to replace barcodes, for example in retail environments, is well appreciated, the cost of providing such transponders for each product is currently prohibitive.